JS: defer parsing of javascript
<script type="text/javascript">
function downloadJSAtOnload() {
var element = document.createElement("script");
element.src = "defer.js";
document.body.appendChild(element);
}
if (window.addEventListener) {
window.addEventListener("load", downloadJSAtOnload, false);
} else if (window.attachEvent) {
window.attachEvent("onload", downloadJSAtOnload);
} else {
window.onload = downloadJSAtOnload;
}
</script>